The Neurochemistry of Smartphone Addiction

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Smartphone addiction is correlated with neurochemical imbalances in the brain, according to a first-of-its-kind study presented today at the 103rd Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) in Chicago.

This research was led by Hyung Suk Seo, who is a professor of neuroradiology at Korea University in Seoul, South Korea. The co-authors of this soon-to-be-published paper are Eun-Kee Jeong, Sungwon Choi, Yunna Kwon, Hae-Jeong Park, and InSeong Kim.

For this study, the neuroradiologists used magnetic resonance spectroscopy (MRS)—which is a specialized type of MRI that measures the brain's chemical composition—to gain unique insights into the brains of people who are believed to have developed addictive patterns in their use of digital technology. Interestingly, another study from July 2017 by researchers at Ben-Gurion University in Israel found that heavy smartphone users display changes in social cognition, impaired attention, and reduced right prefrontal cortex (rPFC) excitability.

To identify the severity of smartphone or internet addiction, the South Korean researchers used a standardized smartphone-internet addiction questionnaire. The questions were designed to elucidate the extent that excessive screen time affects someone's daily activities, face-to-face social connectedness, productivity, sleeping patterns, and feelings.

"The higher the score, the more severe the addiction," Dr. Seo said in a statement. Notably, Seo et al. found that smartphone-addicted teenagers had significantly higher scores in depression, anxiety, insomnia severity, and impulsivity.

The cohort for this study involved 19 teenagers who had been diagnosed with internet or smartphone addiction and a control group of 19 gender- and age-matched teens that were not addicted. A dozen of the smartphone-internet addicted young adults underwent nine weeks of cognitive behavioral therapy (CBT) that was designed to reduce addictive behaviors.

MRS brain imaging scans were conducted on the addicted youth before and after behavioral therapy. A single MRS analysis was conducted on the non-addicted control group.

The researchers were specifically interested in measuring two neurotransmitters believed to be markers for various types of addiction: First, they honed in on the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), which slows down brain signaling. Second, they analyzed levels of glutamate-glutamine (Glx), which is an excitatory neurotransmitter that causes neurons to become more electrically stimulated.

The MRS results illuminated that the ratio of GABA to Glx was significantly increased in the anterior cingulate cortex of smartphone- and internet-addicted youth prior to CBT. Seo speculates that “increased GABA in the anterior cingulate gyrus in internet and smartphone addiction may be related to the functional loss of integration and regulation of processing in the cognitive and emotional neural network.”

Previous research has shown that too much GABA is correlated with a number of side effects that can paradoxically range from drowsiness to high-anxiety. In a statement, Dr. Seo said, “the ratios of GABA to creatine and GABA to glutamate were significantly correlated to clinical scales of internet and smartphone addictions, depression, and anxiety.”

"The increased GABA levels and disrupted balance between GABA and glutamate in the anterior cingulate cortex may contribute to our understanding the pathophysiology of and treatment for addictions," Hyung Suk Seo concluded.

The good news for anyone who may be addicted to his or her smartphone is that after cognitive behavioral therapy, GABA to Glx ratios significantly decreased or normalized in the young adults diagnosed with smartphone-internet addiction.

Obviously, based on the small cohort size and preliminary nature of this first-of-its-kind research, more extensive clinical studies are necessary before we can truly understand the clinical implications of the correlation between GABA to Glx ratios and smartphone addiction.